Dual test tube



FIG. 1 is a perspective view of a dual test tube according to our new design;

FIG. 2 is a front elevation view of thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a left side elevation view thereof;

FIG. 5 is a right side elevation view thereof;

FIG. 6 is a top elevation view thereof; and,

FIG. 7 is a bottom plan view thereof.

The dash-dash broken lines showing in the views illustrate unclaimed portions of the dual test tube and form no part of the claimed design. The dual test tube is shown with symbolic breaks in length. The appearance of any portion of the article between the break lines forms no part of the claimed design. 

CLAIM The ornamental design for a dual test tube, as shown and described. 